Spring-lok is a simple carbon steel diverless connector that self activates at target penetration. Although often used to join piles to structures the device may be used for any tube to tube connection to attach subsea structural elements, sub-assemblies or modules remotely.

Dual indicator systems provide a foolproof visual confirmation of engagement. The primary system includes eight indicator pins that displace outwards as the pile collar aligns with the springheads and on engagement they return within the sleeve. A secondary system utilises a simple red pile line that appears within a viewing hole.

This patented ‘pile and forget’ solution makes the connection instantaneously, requiring no secondary offshore tooling /operations or personnel. It is available in a complete range of API tubular sizes. Units have been fabricated from 14 to 42 inch diameter – delivering load capacities from 50 Te to 5000 Te.

If you are considering either standard piling applications or have a project specific functional requirement please contact us to discuss the range of options.


Production/Injection Manifolds
Subsea Isolation Valve Structures
Crossover Valve Assemblies
Protection Structures
Subsea Riser Bridges
Hot Tap Structures
Renewable Energy Structures
Wellhead Protection Structures
Jacket and Drilling Templates
Flowline Termination Assemblies
Pipeline End Manifolds
Submerged buoy riser connections
Suction Pile Applications
Subsea Module Connections

Key features & advantages

Simple Diverless Operation
Fixed Low Cost
Instantaneous (zero vessel time)
Robust Lloyds approved design
Eliminates all specialist offshore spread
Eliminates all specialist offshore personnel
May be placed at any height within pile sleeve
Wide range of capacities from 50 to 5000 Te
Totally unaffected by water depth
Zero deck space required
Lightweight – 24” insert adds less than 550 kg to each pile sleeve
Compatible with standard hammer/pile equipment
Full range of API tubular piles (14” to 42”)
Built in pile centralisers
External engagement Indicator
Factory Acceptance Tested
Allows full SIT
Full metal to metal bearing
Provides electrical connectivity
Dedicated C.P system
Inspection class ROV only required


Spring-loks are provided either as a fully finished connectors within a section of pile sleeve or ‘can’ or alternatively as part of a complete pile sleeve.

The units are fabricated, adjusted and machined prior to leaving the workshop. The dedicated anodes are fitted and internals are machined following assembly and welding to ensure exacting tolerances are met.

Each unit is subject to complete FAT before packing and transportation to the main Fabricator where the units are integrated into the structure.

The fabrications are carried out under a fully implemented BS EN ISO 9001 approved Quality Management System.


ECL provide full FAT and also procedures and attendance at SIT Tests to demonstrate full functional performance of the Spring-lok units prior to load-out.

Design & documentation

Supply includes a complete project specific documentation pack including:
Spring-lok Design Report with :
LRS Approved Generic Design of Springs and Springheads with Element stress evaluation and unity check report
Pile insertion load assessment
Support ring design
Cathodic Protection design
Optional Contingency Pin Design
Optional FE Analysis
Optional fatigue assessment
Other Documentation provided includes:
AFC drawings
Handling Procedures
Operating procedures
Fabrication data dossier
Welding/NDE/Coating procedures

Download Product Sheet